Seguin's Lobelia is an erect leafy perennial 1-2.5 m tall, with a long spike of two-lipped flowers. Leaves are elliptic and finely toothed. Flowers are purple to mauve with 2-lobed upper lip and 3-lobed lower lip, and a curved flower tube, to 2.5 cm long. Sepals are linear, with gland-tipped teeth. Stamens are fused into a curved column. Seguin's Lobelia is found at altitudes of 1800-3200 m in the Himalayas, Assam and Arunachal. Flowering: August-October.